Reversible contrast illuminated control indicator



Sept 60' R. c. BASSETT, 3R 2,953,668 REVERSIBLE CONTRAST. ILLUMINATED CONTROL: INDICATbR I Filed May 14, 1959 FIG.2

POWER INVENTOR;

I RAYMOND c. BASSETT JR.,

BY TZ CMZM ms ATTORNEY.

United States Patento REVERSIBLE CONTRAST .-ILLUl\ HNATED .CONTROL INDICATOR Raymond -C. Bassett, Jn, Fayetteville, N.Y., assignor to General Electric company, 'a :corporationof :New "York .FiledMay 14, 1959, SenN0. 813,128

*l l 'Glaims. (Gl. 200--167) inventionrelates to control indicators, and more particularly, relates to "an illuminated control indicator capable of visually indicating thestate of a'tworstate ,device operated rthereby.

iMiountedzon the .controlipanels tof .operatingequipment such as the control panel of zradareequipment 'aretmnny twowstate devices such :as electrical switches. To :enable .theoperatortoknow whatoperating circuitry is =controlled by-.each-;of SUGhfiSWitChSS a label identityingthe function ispositionedadjacent ;the-switch. .To-enable:equipmentioperationtunder all conditions of ambientlighti-ng including therlowilevelilighting for .radancontrol centers, zthe label is illuminated by. a panel mounted lamp. Toindicate the state of the :two-position switch, :e g. -.onofi, a separate indicatonsuchwaseapanel-ilightiisprovided. In an arrangement known to the art the panel iindieator light, such asiaigreen or redzlight, is illunnnatedwhen power is appliedto tiho circuit .controlled :by the switch .byscoupling theElampfilamentzin parallehwithithe;circuitry orrbyrapplying ower to thetfilament by separate contacts closedby=switchaoperation.

:However, the panel:density:of:present equipments some times;precludes the use of separate indicators-and controls. This is;par,ticularly truein air-borne :applications .where space is at a premium. :Further, the highz-panel density sometimes precludes adequate spacing between controls and indicators to adequately ensure unmistakeable operationthereofduring-rapid operator scan.

it is, therefore, oneobject ofmyinvention to provide a control :indicator which carries a ititlfi .thereon :to identify the control .function and in whichIhe contrast between the tcharacters in the title and :the background is reversed toindicatethe function state.

It is a further object of this invention to provideqaniinformation indicator for a function having :two states vof operation .in which the ittunction. is :identified :by characters presented against a background and in Whichthezstateuf the function is identified by the "relative contrast between thecharacters-and the background.

It is :a {further object of :this invention'to :providean illuminated control indicator to control :a :function :by movementthereof and in which the functionis identified by .-a :title -presented against a background. ihe operating statetofthe control function is :identified'by thestate of :the contrast between the title.and :the background e.g. a white title against a black background or alblac'kititle against a white background.

.Other.=objects and advantages of :myinvention :will :ap pear hereinafter.

.In accordance with these objects :I have lprovidedzin one embodiment of my invention an illuminated control I111- dicator "comprising a clear :plastic ;bar with the function title engraved in the back. l 'he :function title is filled with an opaque white pigment. A-frosteddifiuserisiapplied to the back of the plastic bar. The-control indicator engages :-a switch controlling the state tot anaassociated function. .In one state the :title :is .edge-lit through :the clear plastic and will appear as white letters on a black background. When the control indicator is moved to switch the .functionto the second state, the edge lighting is extinguished and the indicator is illuminated through the diffuser. Sincethe characters comprising the title are opaque, the title willnow appearas black lettersupon a whitefbackground. Thus, the control indicator indicates the function controlled by characters and .indicateszthe function state byreversiblerelative contrast betweerrthe characters and background.

Apreferred embodiment is shown in the drawing which: .Figure 1 isaisectionedview. showing of oneembodiment of the control indicator in accordance with thisinvention. .Figure 2 is a plan viewof the face of the indicator showniin figure .1 .inone state of indication.

Figure 3 isle-plan view of the face-of the indicator shown :inifigure .1 in .theother state of indication; and I ,Figure 4 is a :partially sectioned viewof another em- .bodimentofen indicator in accordance withthis invention. Referring to Figure .1there.is-shown a panel 10 of an operating equipment .such as a radar set. .A switch mounted on :the face .of .the panel controls a function .within the equipment. The barrel 12 of theswitch iszinserted through .an aperture in the control panel and is secured .theretobyzthe .co-action of nuts 14 and .16 threadably engaging .the switch .barrel 12. A lock Washer 18 may be interposed .to secure nut 16 and prevent loosening thereof under vibrational stress. The switch is theusual "fpush push type having. aicap.20 .movably mountedonthe barrel thereof. .The-cap is spring :biasedandsuitablyrestrained .by an .internalstop so that its rest position will he .in :a .first .axial position. .Upon pressing the cap thatit moves axially in .telscopic relationship -to.the-:barre1, theswitch will .make a connection betweenone senof contacts and break a-connection between anotherset of -con-. tacts. Therconnectionsso established remain in-thisgposi tionumtilathecapis again depressed from its rest position, The switch .is similar to the dimmer "switch installed :on cars, but -I have found it preferable to employthenniniature'switches :of :the same type which are commercially available. This-describes amechanical bi-stablesswitch; It will-workequally well withan electricalbiestab-le (commonly a flip-1lop or multibrater) circuit, which 1h switchtonlyffurnishes a pulse to. j Atrect'angular housing .22 is mounted on :tllfi panelielll by screws .24. Mounted Within the-housing isaaniilluminated control indicator generally designated .26. The control indicator is movably-tmounted withinztherh'ousa ing and .is guided thereby -by frictional engagement therewith or may be guided .by suit-able guide channels :iand coasting .runners in conventional fashion dependent .en the -application intended. The control indicator 126 is in operating contact with the cap 20-of the switch, :the spring bias of which serves to return the indicator to:fa rest position in peripheral contact with a resilient seat 28. The resilient seat 28 :may he a pad formed {of fibrous material :to cushion the indicator as it :returns to the rest-t, position sand to tligh-tzseal :the housing toiprea vent escapeof illumination therefrom Nvhichnnight :di-stract the-operator of theequipment. The indicator comprises ta -clear plastic .face ;plate 30. with '-.the function title characters 32 engraved .in the back thereof. .I-"he function title characters 32 are filled with anopaque white pigment such as titanium dioxide. A diffuser panel 34 is mounted behind the {face plate with an air gap 35 therebetween. Toindicat-eca change in state of the function controlled by -tthe ew itch', Jthe relative contrast between the :b-ackgnoundiand 1the i funnfltion-title is reversed. One state of the ffllllGfiOl'l'FWill the indicated by white -.characters against. a dark background which may be a screw type socket or a bayonet socket dependent on the lamps selected. The socket is mounted on a panel 40 secured to the back of the diffuser by means such as a screw 42. For simplicity of mounting it is usually preferable to form this panel of an insulator such as a standard grade phenolic through which the terminals of the lamp socket protrude. Lamp 37 is provided with a similar socket and mounting arrangement. Leads 44 and 46 and returns 48 and 50 extending from lamps 36 and 37 respectively serve to couple the lamps serially. The serially coupled lamps are connected across terminal 52 of the switch and terminal 54 of battery 56, the other terminal of which is connected to terminal 58 on the switch. For indication of this state the switch will connect terminals 52 and 58 internally so that battery power is applied across the serially coupled lamps. The illumination from lamps 36, 37 indicated by arrows 60, 62 respectively are connected to the face plate 30 of the indicator switch by light pipes 64, 66 respecively. The light pipes are formed of clear plastic material having polished reflector surf-aces 68 and 70 to reflect light incident thereupon. The surfaces are at 45 to the light path, which is then deflected through two right angles and is directed to the clear plastic face as indicated by the arrow-heads on the light paths 60 and 62. Since the light is then incident upon the etched characters of the function title, the title will appear as white letters upon a dark background. An opaque barrier 72 separates the light pipe from the diffuser panel so that no illumination will penetrate the diffuser and it will remain dark to the eye of the operator.

Contrast reversal is provided for by the placement of lamps 73, 74 mounted within the diffuser panel. Each lamp is mounted within a socket 76 which, in turn, is mounted on an opaque panel 78 secured to the diffuser panel by means such as screws 80. Again, I have found it preferable to form these panels of an opaque insulator such as a phenolic. The panel 78 bears against a shoulder 82 formed in the opaque barrier 72 to form a continuous opaque barrier after mounting of the panels therein. Leads 84 and 86 and leads 88 and 90 from the respective lamps 73 and 74 are led out through the panel and serially couple the lamp filaments across switch terminal 92 and terminal 54 of the battery 56. Depression of the control indicator 26 will cause the switch to open the connection between terminal 52 and 58 thereof and complete a connection between terminals 58 and 92 thereof. The change in connections will remove power extinguishing lamps 36, 37 and lighting lamps 73, 74. Light from lamps 73 and 74 will enter the diffuser panel 34 through wall 93 of the mounting hole therein and pass in a path indicated by arrows 94 to the boundary surface between the diffuser panel 34 and the air gap 35. The diffuser panel 34 is preferably constructed of plastic containing diffuser material suspended therein so that the illumination of the boundary is even. Since the characters are filled with an opaque white pigment, the characters will interrupt the light path passing from the boundary to the observer through the air gap and the face plate, and the observer will view the characters as black letters upon a white background as shown in Figure 3.

It is convenient to form the barrier 72 of structural material such as a phenolic and bond the diffuser panel 34 and the face plate 30 thereto.

When the circuit represented by the utilization circuit 95 is of such nature that it requires voltage of the same order of magnitude as that supplied to the lamps, the circuit can be controlled by coupling the circuit across switch terminal 52 and the battery terminal 54 by respective leads 96 and 98. A typical application for such circuitry would be the supply of heater voltage to the tubes in an electronic circuit. In applications where higher voltages or different operating functions are required, the utilization circuit 95 may include a suitable power supply connected to the circuitry by relays operated by battery power.

It will be noted that additional switch contacts operable by movement of cap 20 may be provided for function control purposes.

In this manner, I have provided in a single control indicator, an illuminated indicator having the title of the function control thereby presented on the face thereof. Thus, the operator is unmistakeably guided to the proper control for activation of the function in the circuitry. Depressing the control indicator will operate the control function and the operation thereof is simultaneously reflected by the reversal of contrast between the title characters and the background. I have found the operator can be trained very quickly to understand the state of the function by inspection of the relative contrast between the function title and the background. Illumination intensity can be suitably controlled by variation of the potential of battery 56 or by separate voltage control circuitry to give the proper illumination intensity for the application intended.

In some applications it is desirable that the relative contrast be made higher than that obtainable with the embodiment shown in Figure 1.

In such applications the embodiment shown in Figure 4 may advantageously be employed. In Figure 4 there is shown a control indicator comprising a clear plastic face plate 99 containing a title block 103 in which character titles 32 are engraved and filled with an opaque white pigment such as titanium dioxide. To indicate one state of operation, lamps 36 and 37 are provided. The illumination therefrom is guided by the respective light pipes 64 and 66 to the face plate 99 for illumination of the character titles 32 by side lighting.

To indicate the other function, state lamps 73 and 74 are provided. The lamps are mounted within a diffuser panel 34. Interposed between the diffuser panel 34 and the face plate 99 is a polaroid screen 100 held out of contact with the face plate and difluser panel by gaskets 101. The screen 100 is circularly polarized. The circularly polarized screen 100 will inhibit light penetration therethrough and reflection from the diffuser panel 34. Thus, the circularly polarized screen 100 has the effect of darkening the background in the mode shown in Figure 2.

To enable change of function and title the face plate title block 103 is removable. Edge lighting of the characters engraved therein is provided by the diffuser peripheral surfaces 102 and 104 in the face plate 99 and title block 103 edges respectively which engage in abutting relationship when the title block 103 is mounted in the indicator.

It will be understood that the invention may be variously modified and embodied within the scope of the subjoined claims.

What is claimed is:

1. An illuminated indicator adapted to indicate function states by reversible contrast between a function title and a background which comprises a transparent face plate having title characters engraved in one surface thereof, said characters being filled with an opaque pigment, a diffuser panel mounted adjacent the engraved surface of said face plate, means for edge lighting said indicator through said transparent face plate to indicate a first state, and means for simultaneously extinguishing said edge lighting and for illuminating the indicator through said diffuser panel to indicate a second state.

2. An illuminated indicator adapted to indicate one of two states of a function which comprises a transparent panel having a character representation of said function engraved in one surface thereof, said engraved characters being filled with an opaque white pigment, means responsive to one function state for edge lighting said transparent panel thereby to indicate said function in white let-ters upon a dark background; and means responsive to a second state of said function for illuminating a surface adjacent said engraved title surface to thereby indicate said function in dark letters on an illuminated background.

3. An illuminated control indicator adapted to control a two-state function and to indicate the function state by relative contrast between the function title and a background which comprises a switch, a control indicator in operating engagement with said switch, said switch adapted to change said function to the first state thereof in response to a first movement of said indicator and adapted to change said function to the second state thereof in response to a second movement of said indicator, said indicator comprising a transparent face plate having characters representing said function engraved in one surface thereof, said characters being filled with an opaque pigment, means responsive to said first movement for edge lighting said transparent panel, a dilfuser panel mounted adjacent the engraved surface of said transparent panel, and means responsive to said second movement for illuminating said indicator through said diffuser panel.

4. An indicator in accordance with claim 1 which includes a circularly polarized screen interposed between said diffuser panel and the engraved surface of said face panel.

5. An indicator in accordance with claim 2 which includes a circularly polarized screen interposed between said diffuser panel and the engraved surface of said face panel.

6. A control indicator in accordance with claim 3 in which a circularly polarized screen is interposed between said diffuser panel and the engraved surface of said face panel.

7. A control indicator in accordance with claim 3 which includes a housing adapted to prevent the escape of illumination from the periphery of said indicator.

8. A control indicator adapted for mounting on high density control panels for the control of a function and the simultaneous indication of the function state by reversible contrast between the function title and a background which comprises a housing, a switch contained within said housing, an indicator movably mounted within said housing in operating engagement with said switch, said switch adapted to cast said function into a first state upon a first movement of said indicator, said switch adapted to cast said function into a second state upon a second movement of said indicator, said indicator comprising a transparent face plate with characters representing said function engraved therein, said characters being filled with an opaque pigment, means responsive to said first movement for edge lighting said transparent panel, a diffuser panel adjacent said engraved surface of said transparent face plate, and means responsive to said second movement for illuminating said indicator through said diffuser panel.

9. An illuminated indicator adapted to indicate one of two states of a function comprising a transparent panel having a character representation of said function engraved in one surface thereof, said engraved characters being filled with an opaque pigment, means responsive to one function state for edge lighting said transparent panel and means responsive to a second state for back lighting said panel.

10. An illuminated indicator in accordance with claim 9 in which said panel is provided with a diffuse edge surface and said edge lighting means comprise light pipes terminating in diffuse ends abutting said edges of said panel.

11. An illuminated indicator in accordance with claim 1 in which said face plate includes a removable title block, said title block having a diffuse peripheral surface which engages a mating diffuse surface in said face plate in abutting relationship therewith.

No references cited. 

